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Field  Columbian  Museum 

Publication  36. 

Geological  Series.  Vol.  I,  No.  6. 


CONTRIBUTIONS    TO 

THE   PALEONTOLOGY  OF    THE 

UPPER    CRETACEOUS 

SERIES 


BY 


William  Newton  Logan,  A.M. 


Oliver  Cummings  Farrington,  Ph.D. 
Curator,  Department  of  Geology. 


Chicago,  U.  S.  A. 
April,   1899. 


CONTENTS. 


Introductory  Note,     . 
The  Genus  Scaphites     . 

Scaphites  warreni,    . 
Prionotropis  woolgari,   . 
The  Genus  Ostrea,     . 

Ostrea  beloiti, 
Fasciolaria, 
Fusus, 

Astrocaenia  conica, 
Pseudo-perna  wilsoni,    . 


Page. 
205 
207 
210 
211 
213 
214 
214 
215 
215 
215 


ILLUSTRATIONS. 

Opposite 

Plate.  page. 

XXII 209 

XXIII 210 

XXIV .         .         .         .         .  211 

XXV 214 

XXVI. 215 


INTRODUCTORY  NOTE. 


The  specimens  described  in  this  paper  were  collected  by  the 
writer  at  different  times  while  studying  the  geological  formations  of 
Kansas.  The  Ft.  Pierre  fossils  were  collected  from  the  deposits  bear- 
ing that  name  in  the  extreme  northwestern  part  of  the  State.  The 
Benton  fossils  were  obtained  from  outcrops  of  that  formation  in  the 
central  part  of  the  State,  in  Osborne,  Lincoln  and  Mitchell  Counties. 
The  Niobrara  species  were  collected  from  outcrops  on  the  Smoky 
Hill  river  in  Ellis  County,  and  from  outcrops  on  the  White  Rock  in 
Jewell  County. 

Some  of  the  Benton  forms,  particularly  the  gastropods,  were 
taken  from  calcareous  nodules  which  were  so  thoroughly  indurated 
that  the  shell  could  not  be  obtained  in  a  form  complete  enough  to 
warrant  specific  determinations.  Nevertheless,  they  are  figured  and 
the  best  description  possible  from  the  material  is  given.  The  remain- 
ing specimens  are  well  preserved. 

A  comparison  of  some  of  the  species  of  the  same  genus  led  the 
author  to  a  study  of  the  distribution,  ontogeny,  and  phylogeny  of 
some  of  the  genera.  The  results  of  this  study  are  included  in  the 
present  paper. 

The  specimens  treated  of  in  this  paper  are  now  in  the  paleonto- 
logical  collection  of  the  Field  Columbian  Museum. 


THE  GENUS  SCAPH1TES. 


Distribution.  The  genus  Scaphites  belongs  to  the  family  Steph- 
anoceratida)  of  the  order  Ammonoidea.  The  genus  includes  about 
forty  known  species.  Its  geological  range  is  confined  to  the  Upper 
Cretaceous  Series,  but  its  distribution  is  widespread,  as  it  is  known 
to  have  been  an  inhabitant  of  at  least  four  continents.  The  species 
were  no  doubt  marine  littoral  organisms. 

The  history  of  the  genus  forms  an  interesting  record.  The  ear- 
liest known  species  occurs  in  the  Gault  of  Europe  which  seems  to 
form  a  transition  stage  from  the  Lower  to  the  Upper  Cretaceous,  for 
it  is  classed  by  some  authors  with  the  former  and  by  others  with  the 
latter  series.  In  this  earliest  known  horizon  of  the  genus  there  are 
few  species,  and  individuals  are  not  abundant. 

In  the  formation  overlying  the  Gault,  the  Cenomian,  the  primi- 
tive species,  Scaphites  cequalis  Sowerby,  reaches  the  acme  of  its 
abundance.  Up  to  this  time,  however,  few,  if  any,  structural  varia- 
tions have  been  introduced.  But  during  later  Cenomian  time  disper- 
sion began  and  the  primitive  species  made  its  appearance  in  the  Cre- 
taceous seas  of  France  and  Switzerland.  With  the  migration  came 
new  environments  which  resulted  in  a  differentiation  of  organic  struct- 
ure, and  the  consequent  production  of  new  species.  All  of  the  new 
species,  however,  are  closely  allied  to  S.  ivqualis. 

It  is,  of  course,  questionable  whether  environment  is  the  sole 
cause  of  variability.  But  it  is  very  highly  probable  that  in  this  case, 
at  least,  the  change  of  environment  was  one  of  the  prime  factors  in 
the  production  of  the  new  species.  For  it  is  not  improbable  that 
under  new  conditions  bathmism  could  more  readily  assert  itself. 
That  it  did  assert  itself  rapidly  is  shown  by  the  production,  in  a  short 
period,  geologically  speaking,  of  nearly  fifteen  species.  From  this 
it  must  at  least  be  inferred  that  the  change  in  environment  gave  an 
impetus  to  the  growth  force.  It  becomes  more  obvious  in  the  light 
of  the  fact  that  in  the  center  of  dispersion  but  three  or  possibly  four 
species  are  recorded  for  the  entire  geological  range  of  the  genus. 
Furthermore  it  is  not  certain  that  two  of  these  species  did  not  migrate 
to  the  center  of  dispersion  from  the  Eastern  colonies. 

207 


208  Field  Columbian  Museum — Geology,  Vol.  i. 

During  middle  Upper  Cretaceous  times  the  genus  continued  its 
eastward  migration.  From  India  two  or  three  of  the  primitive  types 
are  reported.  From  the  Pacific  coast  of  North  America  one  species 
which -is  very  closely  allied  to  the  early  forms  has  been  discovered. 
During  middle  Upper  Cretaceous  times  came  the  introduction  of  the 
waters  of  the  great  North  American  epicontinental  sea,  and  with  the 
waters  of  this  sea  came  in  some  of  the  primitive  species  from  the 
Western  or  Eastern  waters.  And  here  as  in  the  epicontinental  sea 
of  Europe  conditions  favorable  to  development  were  found.  Bath- 
mism  here  also  found  a  strong  ally  in  environment,  and  the  result 
was  the  production  of  thirteen  or  fourteen  new  species.  But  differ- 
entiation of  structure  was  of  a  greater  degree.  The  development  was 
more  accelerated  and  the  changes  more  marked.  The  individual 
grew  to  much  larger  size;  nodes  were  developed  where  ribs  only  had 
existed;  the  sutures  became  more  complex  and  the  form  more  globu- 
lar. 

One  remarkable  fact  in  connection  with  the  development  of  the 
genus  Scaphites  is  that  its  greatest  development  in  both  Europe  and 
America  took  place  in  a  region  lying  between  parallels  40°  and 
500  of  latitude.  This  may  be  only  a  coincidence,  or  it  may  be  that 
when  the  paleontology  of  the  now  unknown  regions  is  thoroughly 
worked  out  the  present  conditions  will  be  found  to  be  only  apparent 
and  not  the  real  ones.  If  neither  of  these  assumptions  be  correct 
the  explanation  may  be  found  to  lie  in  the  similarity  of  environ- 
ments. 

The  following  is  the  distribution  of  the  species  of  the  genus 
Scaphites.  In  Europe,  S.  (equalis,  S.  obliquus,  S.  texanus,  S.  conradi, 
S.  nicolleti,  S.  hippocrepis,  S.  hugardianus,  S.  ivanii,  S.  compressus,  S. 
conslrictus,  S.  culvieri,  S.  reiformis,  S.  geinitzi,  S.  inlatus,  S.  mul- 
tinodosus,  S.  nodi/er,  S.  ornatus,  S.  quadrispinosus,  S.  tridens,  S.  tuber - 
culatus,  S.  trinodosus,  India,  S.  cequalis,  S.  obliquus,  S.  kingianus; 
North  America,  S.  warreni,  S.  conradi  (3  varieties),  S.  larvceformis, 
S.  vermiformis,  S.  texanus,  S.  nodosus  (3  varieties),  S.  mullanus,  S.  sub- 
globosus,  S.  nicolleti,  S.  cheyennensis,  S.  abyssinus,  S.  iris,  S.  mandanen- 
sis,  S.  hippocrepis,  S.  culvieri,  S.  quatsincensis,  S.  reniformis,  S.  semi- 
costatus,  S.  vermiculus,  S.  verrucosus,  S.  comprimus. 

Ontogeny,  Phylogeny  and  Paleontogeny.  No  description  of  the 
ontogeny  or  phylogeny  of  the  genus  Scaphites  has  as  yet  been  pub- 
lished. As  the  adult  forms  of  the  majority  of  the  species  show  evi- 
dences of  a  degenerative  character,  it  was  supposed  that  the  genus 
was  an  abnormal  type,  and  further  that  the  individual  did  not  per- 


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FIELD  COLUMBIAN    MUSEUM. 


GEOLOGY,    PL.  XXII 


Explanation  of  Plate  XXII 


SCAPHITES   WARRENI.      (Mus.  No.  P  5940.) 

Fig.  I.    Side  view  of  specimen. 

SCAPHITES  NODOSUS. 

Fig.  2.    Side  view  of  specimen. 


-IIXX  3TA. 


0?- 

.03 


Apr.  1899.  Paleontology  of  Upper  Cretaceous  Series — Logan.  209 

petuate  racial  characteristics.  That  these  suppositions  do  not  accord 
with  the  facts  is  a  further  confirmation  of  one  of  the  laws  of  evolu- 
tion. It  is  confirmatory  of  the  law  that  as  characters  of  development 
first  show  themselves  in  the  adult,  so  also  do  degenerative  characters. 
In  other  words  degeneration  takes  place  in  the  inverse  order  of 
development.  The  order  of  development  of  the  Cephalopods,  as 
shown  by  Hyatt,  has  been  in  regard  to  form:  1.  the  straight  shell  ; 
2.  the  arcuate  shell ;  3.  the  loosely  coiled  shell  ;  4.  the  closely  coiled 
shell.  Along  with  this  development  of  the  form  of  the  shell  has 
gone  an  increased  development  in  the  complexity  of  the  sutures. 
Scaphites  is  considered  degenerative  in  form  because  of  the  tendency 
exhibited  in  the  adult  to  return  to  an  early  form  by  a  partial  uncoil- 
ing of  the  shell.  If  this  be  true  degeneration,  it  has  not  as  yet  affected 
the  sutures. 

In  fact  the  phylogeny  of  the  genus  reveals  progression  rather 
than  retrogression.  As  an  illustration  compare  the  suture  of  Scaphites 
warreni .  Meek,  Fig.  1,  PI.  XXII  with  the  suture  line  of  Scaphites  no- 
dosus  Meek,  Fig.  2,  PI.  XXII. 

The  first  is  a  Benton  species  while  the  second  is  a  Pierre  species. 
The  first,  therefore,  is  the  primitive  form  as  regards  time  and  suture. 
Furthermore  the  ontogeny  of  6".  nodosus  reveals  a  stage  which  cor- 
responds with  reference  to  the  suture  very  closely  to  the  adult  suture 
of  S.  warreni.  It  seems  very  probable,  then,  that  the  latter  is  in  the 
line  of  the  direct  evolution  of  the  former  and  represents  an  earlier  stage. 
The  changes  in  form  as  revealed  by  the  two  species  do  not  point  to 
any  marked  degree  of  retrogression.  The  principal  changes  have 
been  an  increase  in  the  size  of  the  individual;  an  increase  in  the 
complexity  of  the  suture  lines;  and  the  development  of  two  rows  of 
nodes,  one  on  the  umbilical  shoulder  and  a  second  on  the  ventral 
border.  In  6*.  warreni  the  ornamentation  consists  of  strong  ridges 
with  a  tendency  toward  nodosity  in  some  individuals.  In  the  young 
of  S.  nodosus  the  ridges  are  well  marked  while  the  nodes  are  entirely 
absent  on  the  umbilical  shoulder  and  not  prominent  on  the  ventral 
border. 

In  the  excellent  work  of  Branco  although  Scaphites  is  mentioned 
in  the  list  of  genera  its  ontogeny  is  not  exhibited.  The  omission  was 
no  doubt  due  to  a  lack  of  workable  material.  And,  indeed,  this  was 
at  first  a  serious  obstacle  to  the  success  of  the  present  writer.  Owing 
to  the  highly  crystalline  character  of  the  calcium  carbonate  which 
preserved  the  form  of  the  shells  many  specimens  were  broken  up 
without  results.  Later,  from  some  young  forms  furnished  by  Prof. 
Weller,  of  the  University    of    Chicago,    the    results    recorded  below 


210  Field  Columbian  Museum — Geology,  Vol.  i. 

were  obtained.  Some  of  the  specimens  although  entirely  opaque  in 
the  outer  whorls  were  very  translucent  in  the  inner  whorls  so  that  the 
suture  lines  were  easily  discernible. 

Fig.  i,  PI.  XXIII,  represents  a  number  of  sutures  as  follows:  a. 
The  first  suture  is  angustisellate  and  represents  the  ananepionic  stage. 
b.  The  second  suture  is  a  transition  from  the  suture  of  Anarcestes 
to  that  of  Tornoceras.  c.  The  third  suture  is  Tornoceras.  d.  The 
fourth  suture  is  a  transition  from  Tornoceras  to  Glyphioceras,  or 
possibly  Prionoceras.  e.  The  fifth  suture  is  Glyphioceras.  /.  Is 
Glyphioceras.  g.  Is  a  suture  on  the  second  whorl  which  is  Gastri- 
oceras  but  is  just  approaching  Paralegoceras.  //.  Is  a  suture  on  the 
third  whorl,  diameter  5mm.,  and  is  the  ammonitic  radical,  probably 
nearest  Pronorites. 

The  suture  on  the  first  part  of  the  fourth  whorl  has  much  the  ap- 
pearance of  the  suture  of  6".  warreni,  and  toward  the  end  of  that 
whorl  reaches  the  adult  form. 

In  Figs.  2,  3  and  4,  PI.  XXIII,  views  of  the  protoconch  are  given 
which  represent  the  phylembryonic  stage  of  the  type  Scaphites 
nodosus  Meek. 

Figs.  7-12,  PI.  XXIII,  represent  six  stages  of  growth  between 
the  close  of  the  brephic  and  the  beginning  of  the  ephebic  stage. 

Fig.  5,  PI.  XXIII,  shows  the  suture  of  the  adult  form  of  S. 
warreni,  and  Fig.  6  that  of  6".  nodosus,  Museum  specimen  No.  3653, 
University  of  Chicago. 

SCAPHITES  WARRENI— Meek. 

Proc.  Acai>.  Nat.  Sci.  of  Phila.,  p.  185.    i860. 

(PI.  XXII,  Fig.  1  and  PI.  XXIII,  Fig.  5.  Mus.  No.  P  5940.) 

Revised  and  Enlarged  Description.  "  Shell  medium  size,  trans- 
versely subovate,  moderately  compressed,  inner  volutions  nearly  cir- 
cular, closely  involute,  and  composing  a  little  more  than  one-half  the 
bulk;  deflected  body  portion  longer  than  the  diameter  of  the  involute 
portion  and  rather  more  proportionally  than  the  inner  turns;  surface 
costate  and  without  proper  nodes;  costae  small  on  the  inner  whorls, 
where  they  do  not  differ  materially  in  size,  but  on  the  body  part 
some,  usually  every  third  or  fourth  one,  become  more  prominent 
than  the  others,  and  extend  entirely  across  from  the  inner  side  to 
and  over  the  periphery,  in  passing  upon  which  they  bifurcate,  or  give 
off  branches  and  assume,  with  these,  a  uniform   size.      The   aperture 


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Explanation  of  Plate  XXIII. 


Scaphites  nodosus— Meek. 

Fig.  i.    Views  of  sutures. 

Figs.  2,  3  and  4.    Views  of  protoconch. 

Fig.  5.     Suture  of  S.  warreni. 

Fig.  6.    Suture  of  adult  S.  nodosus. 

Figs.  7-12.     Young  individuals. 


FIELD    COLUMBIAN    MUSEUM. 


GEOLOGY,    PL.   XXIII. 


8 


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GEOLOGY,    PL.    XXIV. 


0 


Explanation  of  Plate  XXIV. 


Prionotropis  woolgari— Meek.    (Mus.  No.  P  5931.) 
Fig  1.     Side  view  of  specimen. 
Fig.  2.    View  of  suture. 
Fig.  3.     Side  view  of  young  specimen. 
Figs.  4  and  5.     Cross  section  of  young  specimen. 
Fig.  6.     Dorsal  view  of  specimen. 


ipl  'f-vu/i  ..-ii;''.'     ./i -11/     i>i/;>jo'»w  di-i<,nrovjnn-[ 
•Ufmiboq  .1    Tji'-I 

'-■"'■ 


Apr.  1899.  Palkontology  of  Upper  Cretaceous  Series — Logan.  211 

is  oval  in  form  with  a  smooth  periphery;  it  is  turned  inward  toward 
the  coil  of  the  shell. 

"  Septa  are  provided  with  moderately  broad  lobes  and  sinuses. 
The  siphonal  lobe  is  longer  than  wide,  and  bears  two  rather  promi- 
nent lateral  branches,  each  of  which  is  unequally  bifid,  and  digitate. 
The  first  lateral  sinus  is  about  the  size  of  the  siphonal  lobe  and  has 
approximately  the  same  width  at  the  base;  it  is  divided  at  its 
extremity  into  two  unequal  lobes  both  of  which  are  bifid,  the  one 
nearest  the  siphonal  lobe  having  its  lobes  again  subdivided;  first  lat- 
eral lobe,  about  the  size  of  the  siphonal  lobe,  divided  at  its  extremity 
into  two  tripartite  lobes  each  of  which  is  digitate;  second  lateral  sinus 
shallow,  divided  into  two  rounded  lobes  each  of  which  is  slightly 
indented;  second  lateral  lobe  tripartite,  central  division  not  divided, 
other  two  bifid;  third  lateral  sinus  small  bifid;  remaining  portion  of 
septa  not  visible." 

Suturally  our  type  is  very  closely  allied  to  S.  ventricosus  Meek, 
and  it  is  quite  probable  if  they  do  not  belong  to  the  same  species 
that  they  are  varieties  of  the  same  species.  The  specimen  here 
described  is  much  larger  than  Meek's  type  of  S.  warreni,  but  it  has 
the  same  general  form.  It  resembles  the  former  species  in  aperture 
and  suture,  and  the  latter  in  body  shape  and  costae.  It  is  the  belief 
of  the  writer  that  .9.  warreni,  S.  wyomingensis  and  S.  ventricosus  are 
varieties  of  the  same  species. 


PRIONOTROPIS  WOOLGARI— Meek. 

U.  S.  Geol.  Survey  of  the  Territories,  Vol.  IX,  p.  455.    1867. 
(PI.  XXIV,   Figs.  1  to  6.      Mus.  No.  P  5931.) 

Further  collecting  and  study  of  this  form  may  reveal  a  new 
species.  A  comparison  of  the  suture  of  P.  woolgari  with  the  suture 
of  the  form  here  figured  and  placed  provisionally  in  the  above  species 
reveals  many  differences.  However,  these  differences  may  be  only 
such  as  exist  between  the  young  and  the  adult  individuals  of  the  same 
species.  As  the  sutural  differences  seem  to  be  the  only  well  marked 
ones  the  original  description  will  be  given  here  and  the  reader  asked 
to  make  the  comparison  of  the  figures. 

"Shell  attaining  a  medium  size,  more  or  less  compressed  dis- 
coidal,  the  outer  turn  being  proportionally  more  convex  (including 
nodes)  than  those  within;  each  volution  embracing  about  one-fifth  of 
the  next  within,  and  having  its  umbilical  margin  slightly  indented  by 


212  Field  Columbian  Museum — Geology,  Vol.  i. 

the  uncovered  nodes  forming  the  inner  of  the  two  outer  rows  on  the  suc- 
ceeding volution  within;  umbilicus  about  equaling  the  greatest  dorso- 
ventral  diameter  of  the  last  turn.  Young  examples,  half  an  inch  to 
one  inch  in  diameter,  with  costae  linear,  closely  arranged,  of  nearly 
uniform  size,  and  manifesting  scarcely  any  tendency  to  develop  nodes 
but  already  showing  the  forward  curve  of  their  outer  ends  well 
denned,  while  the  peripheral  keel  is  low,  narrow  and  simple,  and  the 
furrow  on  each  side  shallow.  At  a  somewhat  larger  size,  costae 
usually  more  or  less  unequal  in  size,  the  larger  ones  now  beginning 
to  develop  the  two  nodes  at  their  outer  curved  ends,  and  to  become 
a  little  more  prominent  and  compressed  at  their  inner  extremities, 
while  the  rather  more  prominent  keel  begins  to  develop  its  crenate 
outline,  and  the  nodes  nearest  to  assume  their  compressed  form  and 
parallel  arrangement.  On  attaining  to  two  and  one-half  to  three 
inches  in  diameter,  costae,  nodes  and  keel  become  more  prominent, 
the  latter  being  strongly  compressed  and  deeply  and  largely  scal- 
loped, with  divisions  rounded  in  outline;  while  at  this  stage  of  growth 
the  periphery,  as  seen  in  profile,  would  seem  to  be  very  deeply  sul- 
cated  on  each  side  of  the  keel,  but  this  is  due  to  the  prominence  of 
the  row  of  nodes  on  either  side  of  the  same.  Costae,  when  the  shell 
has  attained  a  diameter  of  four  inches  much  depressed  in  the  middle, 
with  the  nodes  at  their  inner  ends  thicker  and  more  obtuse,  and  those 
nearest  the  keel  more  depressed  or  nearly  obsolete,  while  those  of 
the  third  series,  near  by,  become  much  enlarged  and  produced 
obliquely  outward  as  short,  thick,  spine-like  projections.  Soon  the 
outer  compressed  nodes  disappear,  and  the  keel  is  only  represented 
by  separated,  low,  elongated  nodes;  and  when  the  shell  has  attained 
a  diameter  of  seven  inches,  the  costae  are  more  distant,  greatly  ele- 
vated, compressed,  and  almost  wing-like,  but  still  retain  a  large, 
prominent,  subtrigonal  node  or  projection  at  their  outer  ends,  and 
again  become,  as  it  were,  pinched  up  at  their  inner  extremities, 
which  do  not  quite  reach  the  umbilical  margin. 

"Septa  moderately  close  together;  siphonal  lobe  longer  than  wide 
with  three  or  four  short  branches  on  each  side,  the  two  terminal  of 
which  are  largest,  more  or  less  nearly  parallel,  and  merely  serrated; 
first  lateral  sinus  broader  than  the  siphonal  lobe,  more  or  less  deeply 
divided  into  two  subequal  branches  with  short,  irregular  branchlets 
and  digitations;  first  lateral  lobe  somewhat  longer  than  the  siphonal, 
and  tripartite,  with  short,  irregular  branchlets  and  digitations  occa- 
sionally in  small  specimens,  with  the  middle  terminal  branch  propor- 
tionately broad  and  so  deeply  sinuous  at  the  end  as  to  impart  more 
nearly  the  appearance  of   a  bipartite  arrangement  of  the  whole;  sec- 


Apr.  1899.  Paleontology  of  Upper  Cretaceous  Series — Logan.  213 

ond  lateral  sinus  nearly  resembling  one  of  the  divisions  of  the  first, 
and  in  the  adult  with  merely  a  number  of  marginal  digitations;  sec- 
ond lateral  lobe  little  more  than  one-third  as  long,  and  from  one- 
third  to  one-half  as  wide  as  the  first,  generally  tripartite  at  the  end, 
but  sometimes  in  large  specimens,  bipartite  on  one  side  of  the  shell, 
the  divisions  being  very  simple  and  short,  or  serrated;  third  lateral 
sinus  very  small  and  merely  bilobate,  or  in  large  specimens  digi- 
tate along  the  margins;  third  lateral  lobe  hardly  half  as  long  as 
the  second,  and  in  small  specimens  merely  tridentate  at  the 
end." 

The  suture,  shown  in  Fig.  2,  PI.  XXIV,  is  from  a  specimen  evi- 
dently much  larger  than  any  seen  by  Meek.  The  diameter  of  the  sep- 
tate portion  is  more  than  two  inches  and  although  the  non-septate 
part  is  not  known  it  is  probably  at  least  three  inches  in  diameter. 
The  specimens  here  figured  were  collected  from  the  Blue  Hill  shales 
of  the  Benton,  in  Osborne  County,  Kansas. 


THE  GENUS  OSTREA. 


The  genus  Ostrea  has  many  representatives  in  the  strata  of  the 
Cretaceous  System,  although  the  entire  system  comprises  a  part  only 
of  its  geological  range.  Its  distribution  was  as  wide  as  the  distribu- 
tion of  the  genus  to-day  plus  its  distribution  in  the  epicontinental 
seas.  A  few  species  are  common  to  Asia,  Europe,  Africa  and  North 
America.  Five  species  are  common  to  Africa,  Europe  and  North 
America.  Fifteen  species  found  in  Africa  are  also  found  in  Europe. 
One  species  not  found  in  Europe  is  common  to  Africa  and  North 
America.  The  Lower  Cretaceous  seas  furnished  the  greatest  abund- 
ance of  species  and  individuals. 

During  middle  Upper  Cretaceous  times  the  waters  of  the  Ameri- 
can epicontinental  seas  were  too  clear  or  lacked  some  characteristic 
conducive  to  the  life  of  Ostreae,  for  few  species  or  individuals  are 
present  in  the  strata  except  a  very  small  form  which  was  probably 
able  to  adjust  itself  to  the  environments.  This  species,  Ostrea  con- 
gesta,  is  one  of  the  best  known  and  most  widely  distributed  of  the 
genus.      It  is  remarkable  also  for  its  abundance. 

Probably  the  greatest  beds  of  fossil  Ostrea  in  existence  are  in 
the  Lower  Cretaceous  strata  of  Texas.    .There  beds  of  almost  pure 


214  Field  Columbian  Mijseum — Geology,  Vol.  i. 

shells  several  feet  in  thickness,  having  a  meagre  arenaceous  matrix, 
are  traceable  for  miles.  Farther  north  in  Kansas  they  still  form  the 
most  abundant  types. 

OSTREA    BELOITI,   n.  sp. 
(PI.  XXV,  Figs.  7  and  8.     Mus.  No.  P  5944.) 

Shell  thin,  oblong,  moderately  capacious,  and  possessing  more 
than  ordinary  symmetry.  Beaks  are  long  and  sharply  pointed;  fit- 
ting closely.  Lower  valve  deep;  area  broad,  triangular,  with  rounded 
borders,  possessing  a  slight  depression  in  the  posterior-central  por- 
tion; posterior  border,  rounded  ;  anterior  border,  pointed  ;  dorsal 
border,  slightly  concave,  nearly  straight;  ventral  border,  convex. 

Upper  valve,  flat  or  slightly  convex  transversely;  in  general  out- 
line it  is  very  similar  to  the  lower  valve;  area  much  the  same,  perhaps 
a  little  shorter.  Muscular  impression  in  both  valves,  sub-central  and 
indistinct.      Surface  not  rough  or  but  little  imbricated. 

Dimensions — Length,  45mm.;  width,  25mm.;  height,  8mm. 

The  species  occurs  in  the  Lincoln  Marble  horizon  of  the  Benton. 
It  is  not  abundant  and  has  been  collected  from  two  localities  only. 
The  specimen  here  described  was  collected  from  an  outcrop  on  the 
Solomon  river  in  the  Kansas  area. 

FASCIOLARIA  sp. 
(PI.  XXV,  Figs.  1  and  3.      Mus.  No.  P  5941.) 

Shell  a  little  more  than  moderate  size,  stout  fusiform;  spire  con- 
sisting of  three  rather  convex  volutions.  The  body  whorl  large  and 
possessing  in  the  central  region  a  flat  area;  whorl  merging  into  a 
rather  short  canal  which  is  slightly  curved;  last  whorl  (body)  and 
canal  more  than  equalling  the  length  of  the  spire.  Surface  ornamen- 
tation not  distinct  in  specimen,  hence  the  difficulty  of  determining 
the  species. 

Several  fragmentary  specimens  which  probably  belong  to  the 
genus  Fasciolaria  were  collected  by  the  writer  from  the  septaria  of 
the  Blue  Hill  shales  (Benton).  The  material  is  in  such  a  condition 
as  not  to  warrant  specific  determination.  They  are  figured  and  men- 
tioned only  for  the  purpose  of  making  our  literature  as  complete  as 
possible  and  with  the  hope  that  in  the  future  better  material  may 
be  obtained  through  the  suggestion  of  the  presence  of  such  forms. 


J'V 


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m 

: 

. 

I 


Explanation  of  Plate  XXV. 


Fasciolaria,  sp.    (Mus.  No.  P  5941.) 

Fig.  1.     Cast  of  a  small  specimen. 
Fig.  3.     Cast  of  a  larger  specimen. 

Fusus,  sp.    (Mus.  No.  P  5942.) 

Fig.  2.  Cast  of  small  specimen. 
Fig.  5.  Cast  of  type  specimen. 
Figs.  4  and  6.    Views  of  an  indeterminable  Gastropod. 

OSTREA   BELOITI,  ft.  Sp.      (Mus.  No.  P  5944.) 

Fig.  7.     Interior  view  of  left  valve. 
Fig.  8.     Interior  view  of  right  valve. 


^IELD   COLUMBIAN    MUSEUM. 


GEOLOGY,    PL.   XXV. 


LIBRARY 
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URBAN A 


LIBRARY 

UNIVERSITY  OF  ILLINOIS 

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FIELD   COLUMBIAN    MUSEUM. 


GEOLOGY,    PL.    XXVI. 


Explanation  of  Plate  XXVI. 


ASTROCCENIA  CONICA,  tt.  Sp.     (Mus.  No.  P  5946.) 

Fig.  1.    A  longitudinal  section  of  type. 

Fig.  2.  A  transverse  section  of  type. 
Fig.  3.    A  fragment  of  corallum — type. 

PSEUDO-PERNA  WILSONI,  tt.  Sp.      (Mus.  No.  P  5945-) 

Fig.  4.     Exterior  view  of  left  valve. 
Fig.  5.     Interior  view  of  left  valve. 


.IVXX  3TAJS    *=*0    HOITAMAJSXB 


A 


Apr.  1899.  Paleontology  of  Upper  Cretaceous  Series — Logan.  215 

FUSUS  sp. 
(PI.  XXV,  Figs.  2  and  5.     Mus.  No.  P  5942.) 

The  shells  of  these  specimens  are  entirely  absent  and  a  specific 
determination  is  not  warranted  upon  evidences  such  as  are  presented 
by  casts  alone.  The  reader  is  asked  to  compare  the  figures  of  these 
specimens  with  the  figures  of  Fusus  staminea,  Conrad.  The  forms  rep- 
resented here  were  found  associated  with  Rostellites,  and  the  above 
described  species.  ' 

ASTROCCENIA  CONICA,  n.  sp. 
(PI.  XXVI,  Figs.  1,  2  and  3.      Mus.  No.  P  5946.) 

Corrallum  tuber-like,  about  the  size  of  a  medium-sized  orange; 
corallets  inversely  conical,  not  greater  than  8mm.  in  diameter,  calices 
of  the  corallets  of  moderate  depth,  six  sided  but  not  always  distinctly 
so,  with  moderately  thin  interstices  but  bordering  each  other;  colu- 
mella distinct  but  not  prominent;  intersection  of  dissepiments  and 
septae  forming  prominent  carinae;  vertical  septae  extending  more  than 
half  the  distance  to  the  columella,  the  secondary  ones  only  about  half 
the  length.  Specimen  somewhat  weathered  so  that  generic  charac- 
ters are  doubtful. 

This  specimen  is  interesting  as  being  the  only  species  of  coral  as 
yet  described  from  the  Benton  of  the  Interior  Cretaceous.  It  was 
collected  by  the  writer  from  the  Lincoln  Marble  horizon  on  Rattle- 
snake creek  in  Mitchell  County,  Kansas. 

PSEUDO-PERNA  WILSONI,  n.  sp. 
(PI.  XXVI,  Figs.  4  and  5.      Mus.  No.  P  5945.) 

Shell  thin,  capacious,  triangular  in  general  outline  with  short 
beaks  turned  slightly  toward  ventral  border,  and  fitting  closely. 
Lower  valve  thick  on  the  margins,  thin  centrally:  not  as  capacious  as 
upper  valve  and  nearly  flat  on  the  adhering  surface;  fluted  on  margin 
in  some  specimens,  and  lacking  the  symmetry  of  outline  noted  in 
upper  valve;  ventral  border  possessing  a  triangular  excursion  near 
the  central  portion;  dorsal  border,  concave;  posterior  border,  convex. 

Upper  valve,  flat  or  nearly  so  on  postero-ventral  wing,  convex  in 
general;  ventral  margin  in  region  of  beak  crossed  by  slight  ridges  of 


216  Field  Columbian  Museum — Geology,  Vol.  i. 

muscular  attachment;  area  small  and  depressed;  muscular  impression 
prominent  and  possessing  fine  striae  concentrically  arranged;  dorsal 
border  convex;  ventral  border  nearly  straight,  somewhat  wavy;  pos- 
terior border  concave;  shell  becoming  very  thin  at  the  margins;  exte- 
rior surface,  marked  by  fine  wavy  concentric  lines  of  growth  which 
are  cut  transversely  by  slight  depressions  or  partings  of  the  shell; 
interior  smooth,  corneous. 

Dimensions — Length,  38mm.;  width,  42mm.;  height,  10mm. 

This  species  occurs  in  the  Hesperonis  beds  of  the  Niobrara.  It 
was  collected  from  the  outcrops  on  the  Smoky  Hill  river  in  the 
Kansas  area. 


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